Sling and method of making same



y 1948. l. R. MITCHELL 2,442,175

SLING AND METHOD OF MAKING SAME Filed March 9, 1946 2 Sheets-Sheet l INVEN roe FIG.5. LRMITCHELL 14v- TORNEY y 1948- l. R. MITCHELL 2,442,175

SLING AND METHOD OF MAKING SAME Filed March 9, 1946 2 Sheets-Sheet 2 /N VEN r0 1? I.R..MITCHELL' Patented May 25, 1948 Leschen & Sons Rope Company, St.-Lou-is-, M01, a corporation ofMissouri Application M81011 9, 1946, Serial N. 653,395

(Cl-..8=?r-8 )1 5Clairns.

This invention relates. to flexible slings, preferably of six members, or any reasonable multiple of three members, intended for use in hoisting or lowering heavy objects through the use of mechanical contrivances which are equipped with parts for receiving the eyes, or loops, of such slings.

One of the difficulties usually encounteredin producing slings. of this nature, which are generally formed of manila, hemp, or wire rope, is the tendency of the rope to twist while the sling is being formed. I overcome this tendency by forming the sling from a single length of material', which may comprise one. or more pieces, which I manipulate in a novel manner to form the sling, instead of forming it in the: manner common to rope slings. heretofore made. Generally in braiding a sling a twist develops in the braided members, and in order to get the twist out it is necessary to so braid the members as to counteract the twisting, tendency. I overcome this by weaving the sling from the center, through which I get more equal weaving without. any twist, so that throughmy invention the material. is woven. in. a manner not heretofore practiced in the art, which automatically eliminates, the twisting, tendency.

The; present invention. differs from other rope slings in the method of weaving, or braiding, or plait-ing. It consists of manipulating a single length of material so as to form six members, which areseparatedinto three groups, and when these have beenmanipulated into a certain position, the remainder of the operation is performed from the center in such manner as to weave both ends of the sling at the same time, and then the material is locked in this position by inserting a pin,v and then unweaving the two free. endsof the material to the sling center, locking them through the center where the pin has been placed, removing the pin, which served as a temporary locking element only, I and re-weaving them back into the sling,

Another important advantage of my invention is that throughitsuse the sling attains the form of a flexible, cohesive unit, and the capacity of the six members of material which form the sling is very little less than the aggregate capacity of six separate units of the material.

In the drawings- Fig. 1 illustrates a single length ofv material coiled before the weaving 0fthe sling is commenced.

Fig, 2 illustrates the separation of the members into pairs or groups.

ing process.

Figs. 4, 5', and 6* illustrate progressive steps in the weaving and lockingof the braided members. 1 l

7 illustrates the woven sling before the ends have been unbraidedi to approximatelythe center of the sling, and with a temporary locking pin inserted to prevent unweaving of the members;

Fig. 8 is a View similar to Fig. 7- with the free ends shown in their pass through the central portion of the sling tolock the woven members in position, replacing the temporary locking pin shown-in the center of Fig; 7.

Fig. 9 illustrates the Woven sling completed and one end spiced into the other end somewhat distant fromtheterminus thereof; with one end stillunsplicedinto-the sling. r

Fig. 'l'o illustrates the compieted' sling".

The invention comprises a single length oiimaterial of a single unit or a number ofi units, having two free ends A and B. The first step in the manipulation of said material consists. in coiling it to form six parallel members if to. 6-, respectively, withthe free endsA. and. B extend.- ing beyond the same end of the coil, as illustrated in Fig. 1 While I have shown sixunit' members of the material to be woven or braided, any reasonable multiple of three can be employed, At this point the members I to 6:, respectively, are separated toform three pairs, or groups; 15,. 8-,. and 9-, respectively, asillustrated in Fig... 2', with the freeends A- and B preferably. in: the same pair, via, pair 1'.

From this point on the braiding, or weaving, is done by alternately crossing the. side pairs over the center pair in hairbraid fashiom. the beginning of which operation is illustrated in Fig. 3. This braiding or weaving: operation. is commenced by manipulating the members from the center of the sling, which causes both: ends of the sling to be simultaneously braided or formed. This operation is. clearly illustrated in enlargeddetail in Figs. 3, 4,. 5; and; 6;. Fig. 3 the pair 8 drops. down back oi the pairfli, In Fig. 4 pair 1 drops down in front Ofl pair 9, pair 9 now occupying the. uppermost position, pair 1 the intermediate position, and. pair; 81 the; lowermost position. In Fig. 5; pair 9 still. remains: in the uppermost. position. while pair I drops: down back of pair 8'; pair 8e now being-.theintermediate pair, and. pair 1 being in thezlowermost position. InFig', 6: pair 8.! has: been; elevated. to" the. uppermost position back of pair 9, which is now in I proceed now to the locking of the sling, as follows: The free ends A and B are unbraided' to a point just past the temporary locking pin I 6, which is the longitudinal center [5 of the sling, their former paths in the woven sling upon withdrawal being marked by tracers (not shown), and re-inserted back through said center in such manner as to lock the weave in secure position. The preferred method of such locking is, as follows: Both A and B form the center pair over the temporary locking pin I6 when the final weaving movement has been completed. The end A is looped around its adjacent outside pair and secures said outside pair, and then back into the portion Ii of the sling body, and rebraided back into its original path in said sling body, as

marked by tracer (not shown). The end B is looped around its adjacent outside pair and secures said outside pair, and then back into the portion ll of the sling body and rebraided back into its original path in said sling body, as

, marked by tracer (not shown).

The unbraiding and rebraiding of A and B as described have locked the sling braid at the center 15. It will be observed from Fig. 9 that at this.

time the ends A. and B. have led back to their original positions. The free ends A and B may now be secured in any one of various numbers of ways. The method illustrated in Figs. 9 and 10 is the preferred form. In a manner well understood in the art, the free end B is now spliced into the body of the end A, as shown in Fig. 9, and secured tightly in position, and the free end A is looped and inserted, or tucked, into the sling at the point where the sling body commences. The sling has now assumed the position shown in Fig. 10, preferably having the complete end loops i3 andM.

From the above description it is obvious that my method of braiding avoids twisting and equalizes the tension in all members throughout all parts of the sling. The above described braiding can be done in such a manner that a flat braid is formed with the pairs of members side by side in a flat plane, or it maybe done in such a way as to form a rolled edge in the braided sling body. The rolled edge method is preferred and is accomplished by folding over, or rolling over, each pair at the edge of the sling body as it is braided.

. sling and reinserting them back into the braided free ends of the coiled material, grouping said 4. straight portions into three pairs, the two free ends being at the same end of the coil, braiding said three pairs together from the center, and unbraiding said twg free ends to the center of the sling and ire-inserting them back into the braided structure in such manner as to securely lock the braid, and returning said free ends back to the same end of the coil they occupied before they were unbraided.

2. The method of forming integrally from a single length of material a flexible sling, which consists in coiling said length of material into a plurality of straight, parallel portions and connecting end sections, said coiling providing, two

free ends of the coiled material, grouping said straight portions into three pairs, the two free -ends being at the same end of the coil, braiding said three pairs together from the center, and unbraiding said two free ends to the center of the sling and re-insertihg them back into the braided structure in such manner as to securely lock the braid, returning said free ends back to the same end of the coil they occupied before they were unbraided, and splicing said two free ends into the sling. V

3. The method of forming integrally from a single length of material a flexible sling, which consists in coiling said length of material into a plurality of straight, parallel'portions, and cone necting end sections, said coiling providing two free ends of the coiled material, grouping said straight portions into three pairs, the two free ends being at the same end of the coil; braiding said three pairs together from the center, and unbraiding said two freeends tothe center of'the structure in such manner as to securely lock'the braid, returning said free ends back to the'same end of the'coil they occupied before they were unbraided, and providing a section at the center of the sling to equalize any unequal strains that might develop during the use of the sling.

4. The method of forming a flexible sling of a single length of material, which consists in grouping said material into six members and again dividing said members into three pairs with the free ends of said length of material extending beyond the same end of saidsling, simultaneously interbraiding the three pairs of the sling, unbraiding the free end portions of said material approximately to the center of said sling, rebraiding said end portions back into said sling so as to lock the braid, and securing the free ends of said members.

5. A flexible braided sling comprising three groups of members interbraide'd and permanently locked at the sling center, and having two end portions terminating at one endof said sling, said two end portions passing about adjacent outside strands'at the sling center so that each of said two end portions occupies the path originally occupied by it through half the length of the sling.

- IRVIN R. 'MITCI-IELL.

REFERENCES CITED The following references are of record in the file. of thispatentz,

UNITED STATES PATENTS 1 Number Garris l J an. 1939 

